With the augmentation of technology in the recent years, the IEEE 802.11 based standard such as Wi-Fi technology has undergone tremendous growth and shifts. Now-a-days, most of the user equipments (UE) available in the market are not only equipped with cellular functionality but also with Wi-Fi as default in order to connect to the Wi-Fi networks operating in either of the unlicensed frequency bands, 2.4 GHz, or 5 GHz. The versatile character of the user equipments, these days, is acting as driving force to the cellular operators to use ubiquitous and cost-effective Wi-Fi technology in pursuing the HetNet strategy. Accordingly, many operators are now deploying low powered Wi-Fi cells along with cellular small cells at multiple strategic locations identified for a HetNet.
In a conventional cellular deployment environment, suitable powered macrocells are being deployed to cover sufficiently large areas. However, deployment of the macrocells in, isolations, may lead to quick degradation of capacity since the number of user equipment (UE) operating in the macrocells coverage areas have increased.
Therefore, operators are now reinforcing the macrocells deployment with one or more Wi-Fi cells placed at multiple strategic locations within one or more macro coverage areas. This kind of reinforced cellular network is generally termed as Heterogeneous network, in short, HetNet. For a typical HetNet, strategic locations for small cells generally include areas with high density of users, such as shopping malls, airports, railway/bus stations, colleges, etc. Also, these locations might include area with dead-spots, or areas with low macro signal strength, such as indoor establishments or peripheral locations of a macro coverage area. Supplemented with small cells placed at multiple strategic locations, HetNets do not only provide the increased mobile data capacity, but also provide better mobile coverage, thereby enhancing the overall mobile broadband experience.
In a typical heterogeneous network (HetNet), the HetNet comprises a macro base station for providing wide area coverage to serves users. Within the macro cell, several low power nodes, such as micro cells, are employed in service areas having a higher density of users requiring high data rates are denoted. Further, the micro cell integrated with the Wi-Fi radio are also used widely to provide multi-technology hotspot capacity/coverage goals. The operators may also deploy independent and cost-effective Wi-Fi Access points in hotspot areas to offload cellular load, and to meet capacity/coverage requirements of the users. In the HetNet, the macro base station coverage could be used for wide area overlay mobility coverage, while Micro base stations along with Wi-Fi Access points coverage may be used for mobile capacity upgrade. The 3GPP standard defines two types of access; trusted and untrusted non-3GPP access. Non-3GPP access includes access from for instance Wi-Fi, WiMAX, fixed and CDMA networks. Trusted non-3GPP Wi-Fi access was first introduced with the LTE standard in 3GPP Release 8 (2008). Further, the trusted access is often assumed to be an operator-built Wi-Fi access with encryption in the Wi-Fi Radio access network (RAN) and a secure authentication method. In a trusted access, the device (UE) is connected through a TWAG (Trusted Wireless Access Gateway) in the Wi-H core. The TWAG is in turn connected directly with the P-GW (Packet gateway [144]) in the Evolved Packet Core (EPC) through a secure tunnel (GTP, MIP or PMIP). Currently, the telecom service operators are looking for a green field deployment of trusted VoWiFi solution for prioritizing the data services through the trusted Wi-Fi environment for sparing the LTE spectrum resources. In general, cellular operators or the Internet Service Providers (ISPs) incur substantially lesser costs in setting up Wi-Fi access infrastructure compared to mobile broadband networks like 2G/3G/4G.
These days, a seamless environment of data offload between Wi-Fi & LTE is not supported by the outgoing ecosystem of the user equipment or even a handover from LTE to Wi-Fi as prescribed in standard TS 23.402. Further, there exist challenges in an event the radio bearer is deleted for a LTE session and the UE is presents in LTE network, while the UE still tries to establish to the radio bearer again which causes the UE to toggle between both Wi-Fi and the LTE network. Therefore, in view of the above shortcomings in the existing known solutions, there is a need for a system and method which allow offloading or handover of data from the LTE to the Wi-Fi without incurring any toggle of network between the Wi-Fi and the LTE.